I'm quite new to OpenLdap. Actually i've been using it for a few years, but
I have no deep knowlege.
The problem I'm facing is my cosumer replicas are segfaulting.

There were a number of fixes to syncrepl in 2.4.9.

My design:
I have one master with several o=BranchX,dc=example,dc=com This is
provider. I have several (the number is X-1) replicas, consumers.
All consumers are replicating its branch o=BranchX,dc=example,dc=com and
one common branch o=BranchMain,dc=example,dc=com.
The picture is like this:

But it seems you have implemented this by using a single database at
dc=example,dc=com, with multiple syncrepl statements (one for each subtree
that you replicate). As far as I know, this in not supported.